R05.02.060.A.(11)(b)

1. When expected to be in travel status in a single location for more than 30 days, the long-term per diem rate applies. The long-term per diem rate is calculated at 70 percent of the short-term per diem rate and applies on the 31st day forward. When staying more than 30 days a traveler can find less expensive accommodations than regular hotel rates, cook their own meals and have limited incidental costs. 
2. A long‐term per diem allowance equal to 70 percent of the short‐term meal and incidental  allowance rounded up to the nearest dollar (or other rate as approved by the Travel Administrator) shall be utilized when the circumstances of travel are such that the traveler can reasonably be expected to incur expenses comparable to those arising from the use of establishments catering to the longer‐term visitor.