40 Pa. Stat. § 75
All bonds or other evidences of debt held by life insurance companies or fraternal beneficiary societies, authorized to do business in this Commonwealth, may, if amply secured, and if not in default as to principal or interest, be valued as follows: If purchased at par, at the par value; if purchased above or below par, on the basis of the purchase price adjusted so as to bring the value at maturity, and so as to yield meantime the effective rate of interest at which the purchase was made, but the purchase price shall in no case be taken at a higher figure than the actual market value at the time of purchase. The Insurance Commissioner shall have full discretion in determining the method of calculating values according to the foregoing rule, and the values found by him in accordance with such method shall be final and binding. Any such company or society may return such bonds or other evidences of debt at their market value or their book value, but in no case at an aggregate value exceeding the aggregate of the values calculated according to the foregoing rule.
This section shall not be construed to require any life insurance company or fraternal beneficiary society, authorized to do business in this Commonwealth, which shall not elect to value its bonds and other evidences of debt by amortization as herein provided, to do so, but any company or society, electing to adopt the amortized basis, shall continue to have its bonds valued upon that basis.
40 P.S. § 75