The original poster also said that type USE cable is what he has. Type
USE cannot be installed indoors. 338.10 (B) (4) (a) only covers type SE
cable. Type USE cable is under 338.10 (B) (4) (b) which is titled
"Exterior Installations." That section specifically limits the length
of type USE that extends indoors to six feet. What the OP probably has
is type SE because type USE is hard to find in 4 conductor.
338.10 Uses Permitted.
(B) Branch Circuits or Feeders.
(4) Installation Methods for Branch Circuits and Feeders.
(a) Interior Installations. In addition to the provisions of this
article, Type SE service-entrance cable used for interior wiring shall
comply with the installation requirements of Parts I and II of Article
334, excluding 334.80.
FPN:See 310.10 for temperature limitation of conductors.
(b) Exterior Installations. In addition to the provisions of this
article, service-entrance cable used for feeders or branch circuits,
where installed as exterior wiring, shall be installed as required by
Article 225. The cable shall be supported in accordance with 334.30,
unless used as messenger-supported wiring as allowed by Article 396.
Type USE cable shall be installed outside in accordance with the
provisions of Article 340. Type USE shall be permitted to be terminated
in enclosures at an indoor location where Type USE cable emerges from
the ground. The length of the cable extending indoors to the first
termination box shall not exceed 1.8 m (6 ft). Where Type USE cable
emerges from the ground at terminations, it shall be protected in
accordance with 300.5(D). Multiconductor service-entrance cable shall be
permitted to be installed as messenger-supported wiring in accordance
with Articles 225 and 396.