(b) When an agency requires a signed written medical certification by a health care provider, the agency may specify that the certification include—

1. (1) A statement by the health care provider that the medical treatment is for one or more service-connected disabilities of the employee that resulted in 30 percent or more disability rating;
2. (2) The date or dates of treatment or, if the treatment extends over several days, the beginning and ending dates of the treatment;
3. (3) If the leave was not requested in advance, a statement that the treatment required was of an urgent nature or there were other circumstances that made advanced scheduling not possible; and
4. (4) Any additional information that is essential to verify the employee's eligibility.

(c)

1. (1) An employee must provide any required written medical certification no later than 15 calendar days after the date the agency requests such medical certification, except as otherwise allowed under paragraph (c)(2) of this section.
2. (2) If the agency determines it is not practicable under the particular circumstances for the employee to provide the requested medical certification within 15 calendar days after the date requested by the agency despite the employee's diligent, good faith efforts, the employee must provide the medical certification within a reasonable period of time under the circumstances involved, but no later than 30 calendar days after the date the agency requests such documentation.

3. (3) An employee who does not provide the required evidence or medical certification within the specified time period is not entitled to use disabled veteran leave, and the agency may, as appropriate and consistent with applicable laws and regulations—

   1. (i) Charge the employee as absent without leave (AWOL); or
   2. (ii) Allow the employee to request that the absence be charged to leave without pay, sick leave, annual leave, or other forms of paid time off.