delivered the Opinion of the Court.
[ 1 The Department of Corrections appealed directly to this court from an order of the district court granting Ankeney habeas corpus relief, Complying with a remand order of the court of appeals from an earlier appeal, the district court interpreted various
12 Because the lower courts erroneously concluded that for inmates convicted of crimes committed after July 1, 1998, good time credits awardable by section 17-22.5-301, C.R.S. (2014), are to be applied against an inmate's mandatory release date rather than merely to determine his parole eligibility; and because a proper application of the statutory deductions from his sentence to which Ankeney is entitled demonstrates that he has not completed service of his required term of parole, the judgment of the district court is reversed.
I.
T8 Randal Ankeney was convicted of, among other things, class four felony child abuse, for which he was sentenced on January 4, 2008 to a prison term of eight years plus three years of statutorily mandated parole. 1 Accounting for his presentence confinement, the Department of Corrections set his mandatory release date at October 19, 2015. Although he became eligible for parole according to the department's calculations in 2010, he was denied parole by the State Board of Parole.
1 4 On January 27, 2012, almost four years before the date upon which the department initially calculated his release from prison to be required, Ankeney filed a pleading in the district court combining a petition for a writ of habeas corpus and a complaint for relief in the nature of mandamus. His pleading sought an order compelling the recalculation of his mandatory release date and, based on that recalculation, his immediate release from the custody of the department. In this pleading Ankeney asserted that he was statutorily entitled to good time and earned time credits beyond the credits allowed by the department and, importantly, that all of the good time and earned time credits to which he claimed entitlement should have been applied not only to determine the date on which he would become eligible to be considered for parole, but also to the calculation of his mandatory release from prison. According to his own calculations, his release from prison to begin serving his three-year term of parole became mandatory on Novеmber 19, 2011. The district court agreed with the department's statutory interpretation, denied habe-as relief, and dismissed the complaint for relief in the nature of mandamus.
T5 On direct appeal from that order, the intermediate appellate court reversed and remanded for reconsideration of Ankeney's claims for both mandamus and habeas relief.
2
Relying entirely on prior pronouncements of this court, the appellate court reasoned that under a "discretionary parole scheme," good and earned time credits merely go to establishing a date for parole eligibility, but under a "mandatory parole scheme," good and earned time credits actually go toward establishing the date upon which a prisoner must be released on parole. Further finding that Ankeney, because he was serving a sentence for a felony committed after 1998, was subject to a "mandatory parole scheme," the appellate court concluded that he had a clear right to have good time credits awardable under section 17-22.5-8301, C.R.S. (2014), and
16 The department chose not to petition this court for further review of that judgment after determining that Ankeney was entitled to be released to parole notwithstanding the court of appeals' judgment based solely on his acerual of earned time credits pursuant to section 17-22.5-405, C.R.S. (2014), which, unlike Ankeney's claim to good time and education earned time, the department did not dispute as applying toward Ankeney's mandatory release date. See § 17-22.5-402(2), C.R.S. (2014) (providing that the full term of an inmate's sentence shall be reduced by any earned time granted pursuant to section 17-22.5-405). Based on Ankeney's earned time credits, the department recalculated his mandatory release date as August 28, 2018 and released him from prison on that date to begin serving his three-year statutorily mandated period of parole.
T 7 After permitting Ankeney to amend his pleading to account for the fact that he had since been released to parole, the district court implemented what it understood to be the mandate of the court of appeals and found that Ankeney should have been released from prison to parole on October 28, 2010. Apparently assuming that the period during which he remained unlawfully incarcerated must be credited against his three-year parole period, the district court additionally found that he should have been released from parole no later than October 28, 2013. On November 18, 2013, specifically referencing the court of appeals' remand order, the district court therefore ordered the immediate termination of Ankeney's parole. 3
T8 In the absence of initial jurisdiction residing in the court of appeals in matters concerning writs of habeas corpus, see § 183-4-102(1)(e), C.R.S. (2014), the department appealed direсtly to this court, challenging the district court's determination of the date upon which Ankeney's release from prison was mandated by statute and its resulting order of immediate release. 4
IL.
1 9 As we have recounted in greater detail elsewhere, see, e.g., People v. Norton,
1 10 Despite some relatively minor alterations, that sentencing system essentially remained in effect until mid-1985, when the legislature enacted what we have referred to as a "modified determinate sentencing system," restoring discretion to the parole board to determine whether, when, and for how long to release an offender to parole, within a range extending from the date upon which the offender became eligible for parole until the date upon which he had fully discharged his sentence. See id.; Renneke v. Kautzky,
111 Over a similar period, the legislature enacted substantial, although not always directly corresponding, changes to the statutes prescribing the calculation of both parole eligibility and ultimate discharge dates. For crimes committed before July 1, 1979, the statutory scheme provided for credit against an indeterminate sentence to account for good time, and what we came to refer to as "trusty time" and "meritorious time." See §§ 17-22.5-201 to -208, C.R.S. (2014); Thiret,
1 12 In 1990, however, the legislature added an entirely new statutory scheme for parole eligibility and discharge from custody contained in part 4 of title 17, article 22.5, expressly making it applicable to all those offenders sentenced for crimes committed on or after July 1, 1979, other than those expressly exeluded, see § 17-22.5-406(1), C.R.S. (2014). Of particulаr note, the new statutory scheme abandoned the concept of good time altogether, Martin,
113 The rationale advanced by Anke-ney for concluding that he had not only passed his mandatory release date but had in fact also been unlawfully confinеd beyond that date for a period sufficiently long to also satisfy the parole component of his sentence 7 rests upon the correctness of his interpretative differences with the department on two critical points. The validity of Ankeney's assertion that he has discharged his entire sentence and is entitled to release even from parole is contingent upon his entitlement to certain credits awardable according to part 3 of article 22.5, which were not separately allowed by the department, as well as his entitlement to have those credits applied to the calculation of his mandatory release date, as distinguished from his parole eligibility date. Apparently understanding that the department had already applied section 8301 good time eredits to the calculation of Anke-ney's parole eligibility date, the court of appeals addressed itself only to the question whether those credits should also have been applied to the calculation of his mandatory release date. Taking Ankeney's entitlement to section 301 good time credits for at least some purpose as accepted, the intermediate appellate court therefore found that because he was subject to a mandatory parole scheme, Ankeney was entitled to have good time credits under section 301, as well as "education earned time" credits, applied toward establishing his mandatory release dаte. While determining his entitlement to the additional education earned time credits he claims pursuant to section 302 turned out to be unnecessary for the district court's ruling that he was entitled to immediate discharge from his mandatory parole, Ankeney continues to assert his entitlement to these additional education credits, should they become consequential to our disposition of his case. 8
114 With regard to the court of appeals' holding that Ankeney was subject to a "mandatory system of parole," which that court found to be dispositive of the question whether an inmate is entitled to the application of good time and earned time credits toward establishing his mandatory release date, the appellate court simply misrеad our applicable jurisprudence. We have consistently held that the good time credits award-able by section 17-22.5-801 and the earned time credits awardable by section 17-22.5-302(1), the specific statutory credits at issue in our applicable holdings, do not constitute the service of an inmate's sentence but rather have significance only for calculating his eligibility for release to parole. Jones,
' 15 The 1998 amendments to the sentencing statutes have been characterized as including a "mandatory parole scheme" or "mandatory parole" only in the sense that for many defendants convicted of committing felonies after that date, a specific, statutorily mandated period of parole attaches as a separate component of their sentences. See Badger v. Suthers,
116 Apart from the court of appeals' rationale concerning mandatory parole schemes, Ankeney argues more straightforwardly that a proper construction of the language of sections 801 and 802 itself requires the conclusion that the credits allowed by those provisions apply to a determination of his mandatory release date. While Anke-ney's reasoning is not without color, the propеr construction of part 3 in this regard has been resolved for almost a quarter of a century, and we see nothing in Ankeney's argument to cause us to revisit that resolution. At least by the time of our decision in Thiret, we made clear that the complex of applicable sentencing statutes and the sequence of their amendments required an interpretation of the good and earned time provisions of part 3 as applying only to the
B.
117 Unlike the good time credits allowed by section 17-22.5-801 and the earned time credits allowed by section 17-22.5-8302(1), we have arguably never had occasion to separately address the impact on mandatory release, of the so-called "education earned time credits" allowed by section 17-22.5-302(1.5). 9 Subsection 802(1.5) was added to the earned time provision of part 3 in 1988, allowing four days per month extra earned time credit for progress in the corrections literacy program, which was implemented that same year, ch. 119, see. 2-8, §§ 17-1-108.5, 17-22.5-802(1.5)(a), 1988 Colo. Sess. Laws 696, 696-97; and the entire subsection was amended only two years later to allow those additional earned time credits for progress in the correctional education program, implemented in 1990, ch. 125, see. 3, § 17-22.5-802(1.5)(a), 1990 Colo. Sess. Laws 971, 976, both programs being included by specific reference in the earned time provision of part 4, see § 17-22.5-405(1)(g). 10 The following year, in place of these extra four days of earned time credit, subsection 302(1.5) was amended to simply provide that an inmate making progress in the correctional education program "shall receive earned time pursuant to section 17-22.5-405." Ch. 80, see. 9, § 17-22.5-802(1.5)(a), 1991 Colo. Sess. Laws 428, 481. Because the earned time granted pursuant to section 17-22.5-405 was already applied by the department against Ankeney's mandatory release date, 11 his claim is limited to the question whether section 302 required that he receive additional credit for prоgressing in the correctional education program and whether any such credit, granted pursuant to section 802, should similarly have been applied against his mandatory release date. Whatever may be the impact of section 802(1.5) on inmates subject to the time computation provisions of part 3, Ankeney cannot fall within that category.
{18 Part 4 of article 22.5 became effective on June 7, 1990. By its own terms, it was made applicable to all those offenders whose crimes were committed on or after July 1, 1979, except those expressly excluded. § 17-225-406. Among other express exclusions, see, eg., § 17-22.5-406(1)(e) (excluding inmates incarcerated prior to June 7, 1990 who had not accrued any earned time prior to
[19 Part 4 establishes entirely new methodologies for determining parole eligibility and discharge from custody. The new formula for determining the former makes an applicable offender eligible for parole after serving fifty percent of thе sentence imposed on him, less any time authorized for earned time granted pursuant to section 405. § 17-22.5-403(1). 12 The new formula for the latter permits discharge from the department only after service of the full sentence imposed upon the inmate, as reduced for most inmates by any earned release time and earned time granted pursuant to section 405. 13 § 17-22.5-402. Section 405 specifies not only the amount of earned time that may be deducted from an inmate's sentence but also the allowable reasons for which earned time may be granted, expressly including making positive progress in the statutorily established literacy corrections program or correctional education program. § 17-22.5-405(1).
20 Part 4 therefore unambiguously pre-seribes formulae for the parole eligibility and mandatory discharge of those inmates to whom the part applies, taking into account nothing more than the sentence imposed on them, or a percentage thereof, and the reductions specified in section 405. These formu-lae do not allow for any reduction of the sentence imposed to account for credits otherwise awardable, including even credits already awarded pursuant to part 3. While disadvantaging inmates by depriving them of credit that had already vested could very well implicate constitutional prohibitions against retrospective legislation, it is clear from the face of the applicable statutory provisions themselves that part 4 was dеsigned to provide inmates already serving sentences at the time of its enactment with equally, if not more, advantageous benefits. With regard to parole eligibility, part 4 automatically reduces the term imposed on an offender to the same extent that he could possibly have been awarded good time ered-its under part 3. 14 With regard to earned time, the provisions of part 4 provide even greater deductions per month than credits allowable under part 3, and with regard specifically to time served before July 1, 1990, limit those deductions only to an amount equal to the credits actually earned by the inmate pursuant to the applicable provisions in effect prior to July 1, 1990.
€21 In short, parts 8 and 4 prescribe separate аnd distinct methodologies for determining parole eligibility and discharge
1 22 Neither party has asserted or offered any construction according to which the release of Ankeney, an offender incarcеrated after June 7, 1990 for a crime committed after July 1, 1979, was not governed by part 4. Quite the contrary, Ankeney's theory of immediate release is contingent upon his sentence having been reduced according to seetion 402. By the same token, there is no suggestion that less than all of the earned time permitted by section 405, which includes credit for positive progress in the literacy corrections program or the correctional education program, was applied against Anke-ney's discharge date. However much, and to whatever effect, education earned time may be awarded pursuant to section 802(1.5) to an offender whose release is not governed by part 4, it clearly could not, therefore, have been awarded to Ankeney or further reduced his sentence in accordance with the formula of section 402.
IIL.
1 23 Because the lower courts erroneously concluded that for inmates convicted of crimes committed after July 1, 1993, good time credits awardable by section 17-22.5-301 are to be applied against an inmate's mandatory release date rather than merely to determine his parole eligibility; and because a proper application of the statutory deductions from his sentence to which Anke-ney is entitled demonstrates that he has not completed service of his required term of parole, the judgment of the district court is reversed.
Notes
. Ankeney also received lesser sentences for stalking and sexual assault, which were ordered to run concurrently with his longer sentence for child abuse. There is no assertion in this case that those convictions or sentences affected his mandatory release date or required term of parole.
. Though it lacked jurisdiction under section 13-4-102(1)(e), C.R.S. (2014), to review the district court's denial of Ankeney's petition for writ of habeas corpus, the court of appeals nonetheless directed the district court to reconsider its habe-as ruling on remand, finding that the habeas ruling was "based on the same erroneous reasoning which underlay its mandamus ruling." Questions concerning the relationship between habeas corpus and mandamus, or of the court of appeals' jurisdiction to address either, are not before us.
. In his "Amended Petition" Ankeney requested only "that the Court deny the relief requested in the Respondents' Brief and issue a Writ of Habe-as Corpus compelling Respondents to show cause why Petitioner should not be immediately released from all incarceration." The district court's initial ruling on the amended petition included nothing more than the words "Order Granting Habeas Corpus Relief," and its subsequent, more detailed "Order"" concluded by expressly ordering "that the petition is GRANTED, on both habeas corpus and declaratory relief, and the petitioner's parole shall be terminated immediately." Notwithstanding the remand order of the court of appeals, neither the amended petition nor the district court's resolution makes any reference to C.R.C.P. 106 or mandаmus relief.
. The department also challenged the district court's authority to terminate Ankeney's parole in the absence of personal jurisdiction over the parole board. At least where the inmate's designation of a custodian was correct at the time the petition was filed; where in lieu of issuing a writ to the custodian as required by statute, the district court ordered service on the attorney general who represented both the department and the parole board; and where the only disputed issues involved the department's calculation of the inmate's mandatory release date rather than any action by the parole board, the department's contention concerning personal jurisdiction lacks mеrit, whether or not the department could otherwise be considered a custodian of an inmate already released to parole.
. Legislative recordings from part 4's original enactment include expert testimony from a representative of the department explaining that, under part 4, "[the phrase good time is done away with. In this scenario, you're just eligible for parole at fifty percent. It's not called good time." First meeting of the Conference Comm. on H.B. 1327 at approx. 7:30 p.m., 57th Gen. Assemb., 2d Sess. (May 7, 1990).
. In 2009, subsection 402(2) was amended to include as well a new category of credit dubbed "earned release time," which similarly would serve to reduce the sentence originally imposed.
. Because we find that Ankeney was not incarсerated past his mandatory release date, we need not decide whether excessive time served in prison may be credited against an inmate's mandatory period of parole. Cf. Edwards v. People,
. In addition, in the statement of prior proceedings section of his Answer Brief, Ankeney baldly asserts (without citation to authority) both that this court lacks jurisdiction over mandamus actions and that the department's failure to appeal the court of appeals' remand order renders any determination we make concerning the applicable statutes moot with regard to Ankeney. Our jurisdiction over any particular class of actions is clearly not limited by a legislative grant of concurrent jurisdiction to an intermediate appellate court, and we have held that we are not bound by the decisions of the court of appeals in a prior appeal even after remand and a second round of appellate proceedings. Giampapa v. Am. Family Mut. Ins. Co.,
. Confusingly, Ankeney's amended petition states that he is entitled to "educational earned time credits" in an amount equal to the maximum number of earned time credits authorized under subsection 302(1), despite thе fact that progress in the correctional education program is not included among the criteria for earned time credits under subsection 302(1), but instead, is listed as a basis for receiving separate credits under subsection 302(1.5). Compare § 17-22.5-302(1), C.R.S. (2014), with § 17-22.5-302(1.5), C.R.S. (2014). Accordingly, despite Ankeney's apparent reference to subsection 302(1), we interpret his petition as raising a separate claim for credits under subsection 302(1.5), and we will address that section accordingly.
. The statute providing for the literacy education program has since been repealed. See ch. 119, sec. 2, § 17-1-103.5(5), 1988 Colo. Sess. Laws 696, 696 (repealing statute providing for literacy education program effective July 1, 1991). Nonetheless, subsection 406(1)(g) continues to include progress in the literаcy education program as potential grounds for an award of earned time under part 4. See § 17-22.5-405(1)(g), C.R.S. (2014).
. In Meyers v. Price, relying on case law construing the good time and earned time provisions of part 3, this court stated that the addition of part 4 did not alter the intent of the legislature that good and earned time credits should apply only for the purpose of determining parole eligibility.
. Certain categories of inmates must serve a greater percentage of their sentences before becoming parole eligible. See §§ 17-22.5-403(2)-(3.5) (providing that certain categories of inmates who have previously been convicted of crimes that would qualify as crimes of violence as defined in section 18-1.3-406, C.R.S. (2014), must serve as much as seventy-five percent of their sentences before becoming parole eligible).
. In 2012, section 405 was amended to allow an additional award of "achievement earned time" credit to inmates who successfully complete a milestone or phase in various programs or demonstrate еxceptional conduct that promotes the safety of persons under the department's supervision. However, unlike earned release time, achievement earned time was not similarly added to section 402, concerning the calculation of an inmate's discharge from custody. We express no opinion as to the effect of achievement earned time credits on an inmate's sentence.
. Section 301 authorizes a maximum good time deduction of fifteen days a month, which the department has interpreted to mean that upon serving fifteen days an inmate is entitled to have the remaining fifteen days in the month credited as a good time deduction, in effect a fifty percent deduction. Ankeney disputes this interpretatiоn and instead understands the statute to permit a fifteen-day deduction only after actually serving an entire month, or thirty days, in effect reducing the credit or deduction to thirty-three percent. The fifty percent formula of section 403 therefore corresponds to the long-time department statutory interpretation and practice and would afford inmates an even greater benefit over the preexisting scheme according to Ankeney's interpretation.
. Such contingencies concerning applicability provide some explanation for the department's failure to draw any clean distinction between the good time credits of section 301 and the corresponding fifty percent reduction of section 403 in explaining its time computations.
